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On sites considered secure (the URL begins with “https://”), Firefox must verify that the certificate presented by the site is valid. If the certificate cannot be validated, Firefox will stop connecting to the site and display an error page indicating “Your connection is not secure”.


If you encounter this problem on several independent HTTPS pages, it indicates that something on your system or network is intercepting your connection and sending certificates in a way that Firefox does not trust. This is indicated by “MOZILLA_PKIX_ERROR_MITM_DETECTED” if Firefox can detect that the connection is intercepted by a proxy. The most common causes are the analysis of encrypted connections by security software or the interception of malware, with legitimate website certificates being replaced by their own.

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Define the configuration parameters

You can enter about:config in the Firefox address bar (confirm the information message if it appears) and search for the security.enterprise_roots.enabled preference. Then, double-click on it and change the value to true and restart Firefox once – this will import all custom certificates from the Windows Trust Store into Firefox and zscaler could become reliable this way.

Adding the CA certificate to the list of security exceptions

You can allow your browser to bypass the secure connection failure message for z/OSMF.

Proceed as follows:

  1. On the error page, click on Or you can add an exception.
  2. Click on Add an exception. The Add Security Exception dialog box appears.
  3. Click on Get a certificate.
  4. Click View to display a window describing the problem with your z/OSMF site.

Check the Issued on. Ensure that the information identifies z/OSMF. The Common Name (CN) value must match the host name of your z/OSMF installation.

Check the fields Issued by. Verify that the certificate was issued by the CA that was used to create the server certificate. By default, z/OSMF uses the zOSMFCA certification authority.

  • To display the other fields of the certificate, choose the Details tab.
  • After checking the certificate, close the dialog box. If you check the Save this exception permanently box, Firefox saves the certificate information to prevent the error from reappearing on the z/OSMF page.
  • Click on Confirm security variance to trust the z/OSMF site.

Your browser now opens with the z/OSMF interface.

Disable HTTPS scanning in your antivirus and security software.

Each security-based software has a security option. This allows you to disable the HTTPS scanning feature. They are available under different names. I mentioned a few of them at the bottom:

  1. HTTPS scanning
  2. SSL Scanner
  3. View the secure result
  4. Do not scan encrypted connections.

Find out what’s right for your security software by visiting the Help section.

Once this change is made, Firefox automatically trusts the certificates associated with the roots of the Trusted Root Windows Root Certificate Store, such as Chrome, Edge, IE and other browsers. Unfortunately, Mozilla refused to enable it by default, but it is still a good option.

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